Effectiveness of Physical-Literacy-Based Online Education on Indices of Physical Fitness in High-School Adolescents: Intervention Study during the COVID-19 Pandemic Period.

There is a global consensus that physical literacy (PL) is an important determinant of physical fitness (PF), but studies have rarely examined the effects of PL-based interventions on PF. The aim of this research was to evaluate the effectiveness of specific online video-based PL intervention on PF indices in high-school students from Croatia. Participants were 423 high-school adolescents (295 girls, 128 boys; 14-to-18 years of age), divided into an intervention group (n = 230) and a control group (n = 193). The intervention lasted 12 weeks. Educational video materials were disseminated to the intervention group by the closed social network during the pandemic period. Variables included height, mass, BMI, cardiorespiratory fitness (CRF), and power, strength, and flexibility indices. Pre- to post-testing design was applied, with two-way analysis of variance for repeated measurement (Time × Group). Applied intervention induced positive effects in CRF (the intervention group improved their capacities, while no changes occurred in the control group) and BMI (the intervention group retained their BMI levels at the pre-testing level, while BMI of the control group slightly increased over the course of the study), with better effectiveness in girls than in boys. No effects were evidenced for other variables. The positive effects of applied educational intervention on BMI and CRF are encouraging knowing that both indices are related to health status.

What drives athletes toward dietary supplement use: objective knowledge or self-perceived competence? Cross-sectional analysis of professional team-sport players from Southeastern Europe during the competitive season.

BACKGROUND: Issues related to knowledge of nutrition and dietary supplementation (DS) are understudied in professional athletes. This study aimed to examine the possible association between knowledge of nutrition and DS (KN&DS) and dietary supplement use (DSU) among professional athletes involved in team sports. METHODS: The sample comprised professional team-sport athletes (N = 912, age: 22.11 ± 3.37 years, 356 females) involved in four Olympic sports: basketball (N = 228), soccer (N = 324), volleyball (N = 154), and handball (N = 206). The participants were tested by previously validated questionnaires to examine their self-perceived competence on nutrition and DS (S/KN&DS), their objectively evaluated (tested) KN&DS (O/KN&DS), sociodemographic and sport-specific variables (predictors), and DSU (criterion). Associations between the predictors and the criterion (No-DSU - Irregular-DSU - Regular-DSU) were determined by multinomial regression analysis for the total sample and separately for the studied sports. RESULTS: DSU was found to be less prevalent in older and more successful players. The O/KN&DS and S/KN&DS were positively correlated with DSU, but S/KN&DS was a stronger predictor of DSU than O/KN&DS. Sport-specific associations between predictors and criterion were identified, with stronger correlations in sports with a higher prevalence of DSU. CONCLUSIONS: Due to the low correlations between O/KN&DS and S/KN&DS in the studied players, this study highlights the necessity for more frequent monitoring of biomarkers of nutritional status and its usage by coaches and practitioners to provide quantitative instruction.

Fluid balance and hydration assessment during the weight-stable preparation phase in elite youth boxers.

This study investigated (i) the prevalence of hypohydration and (ii) association between urinary indices of hydration status and confounding factors (e.g., urine protein content, water intake) in elite youth boxers during their weight-stable phase before competition. Sixteen national champion boxers (all male, 17 ± 1 y) were measured on 3 occasions (baseline, day 3, day 10), 30-day prior to competition. Body mass, total body water, urine specific gravity (USG), osmolality (UOSM) and total protein content (TPC) were evaluated to determine hydration status and fluid balance. Overall macronutrient and water intake were assessed using dietary records. Both UOSM and USG increased from day 3 to day 10 by 16% and 0.4% (P < 0.001), despite athletes being in their weight-stability period, and regardless of ad libitum fluid intake. Hypohydration was universally prevalent among all athletes on both test days with USG: 1.027 ± 0.003 g · mL-1 and UOSM: 1035 ± 108 mOsmol · kg-1. An inverse association between mean UOSM values and mean water intake was observed (R = -0.52, P = 0.04), while TPC was not associated with any urinary dehydration markers (USG, P = 0.51; UOSM, P = 0.61). The present outcomes find that the most prevalent urinary dehydration markers used to classify hydration status in competition exhibit large variability, even during weight-stable periods.

Sport nutrition and doping factors in swimming; parallel analysis among athletes and coaches.

The sport nutrition and doping are known to be important issues in sports, but there is evident lack of studies which investigated those issues in swimming, especially with regard to parallel analysis of coaches and athletes. The first aim of this study was to compare knowledge of swimming coaches and their athletes about nutrition and doping. Also, we have identified interrelationships between studied sociodemographic-, sport-; nutrition- and doping-related-factors. The sample of subjects comprised 55 athletes (20.3 +/- 2.2 years of age; 24 females) and 22 coaches (mean age 36.5 +/- 7.8 years; 4 females) from Croatia (98% of respondents). In the first phase of the investigation we have validated specific questionnaires to determine the knowledge of sport nutrition (KSN), and knowledge on doping (KD). The test-retest correlation and percentage of equally responded queries revealed both questionnaires as reliable. The discriminative validity was proven also since coaches scored better than their athletes on both questionnaires. Athletes declared their coaches as the primary sources of knowledge about nutrition and doping. Among coaches, formal and self-education are equally important sources of information about doping and nutrition. The age is negatively, while the formal education is positively correlated to KD and KSN scores among coaches. Consequently, permanent educational programs about nutrition and doping are emphasized, especially among older coaches and younger athletes.